1. Field of the Invention.
This invention relates to apparatus for injecting dry, sized material into a pressurized pipeline.
2. Description of Related Art
U.S. Pat. No. 1,614,713 discloses a feeder for powdered fuel in which powdered coal is gravity fed from a hopper into a screw conveyer which feeds the coal into a conduit in which the coal is mixed with and suspended in pressurized air. The coal is conveyed for long distances while suspended in the air streams.
U.S. Pat. No. 3,360,301 discloses a loading apparatus for a bulk transport system in which coal stored in a hopper is suspended in a slurry by addition of water through a conduit at the bottom of the hopper. The slurry is removed from the hopper by an outlet conduit concentric and inside the conduit used for addition of water.
U.S. Pat. No. 4,394,132 discloses apparatus for making a coal-in-liquid mixture in which pre-crushed raw coal is fed through a screw auger into a grinding mill for further processing. The mixing of processed coal and carrier medium takes place in a cone-shaped receiver vessel which feeds into the carrier pipe.
U.S. Pat. No. 4,449,862 discloses apparatus and method for injecting a low pressure slurry into a high pressure stream. The high pressure stream is introduced into a disk-shaped vortex chamber with the formation of a low pressure vortex in the chamber. The low pressure slurry is introduced into the low pressure vortex, is captured by the high pressure flow, and is carried from the chamber with the high pressure stream at the high pressure outlet.
U.S. Pat. No. 4,557,636 discloses the injection of solids into a high pressure slurry stream. In this apparatus, a number of injection points are used to connect to the main slurry line. Each injection point uses a vortex junction as described in U.S. Pat. No. 4,448,862.
U.S. Pat. No. 4,824,294 discloses equipment and method for transporting slurries in which a three-chamber-tube-distributor is used. The chambers are in the forms of U-shaped tubes and are periodically filled and emptied with the result that chambers are filled with slurry under reduced pressure and emptied under high pressure. The filling and transport procedures are controlled electronically. This injector requires slurrying of coal prior to injection, numerous controls and valves, and substantial floor space.
None of the prior art references have the characteristics of the present invention, that of a safe, cost-effective means of continuously injecting dry sized coal and other mined materials into a pressurized hydraulic pipeline for transport.